Fitz Part I Flashcards
What is the major advantage and disadvantage of using monoclonal antibodies?
Advant - long half-life
Disadv - Hypersensitivity rxns, human anatomies antibody (“HAMA”) reactions
Major disadvantages to cytokine therapy?
Extremely short half lives, complicated natural of biological response
Why do you add a PEG (polyethlyne glycol) to a therapeutic protein?
It increases the proteins half life and “masks” the protein from immune system. It gets around the problem of the body degrading/eliminating it.
What is important about P-glycoprotein?
Its a main mechanism of resistance to cancer drugs. It pumps the drug out of the cell. Can lead to MDR (multi drug resistance)
What is the primary cause of resistance to MTX?
Reduced expression or mutation of the reduced folate carrier (RFC)
What do increased homocysteine levels indicate?
B12 deficiency!!
What does B12 require to be absorbed in the stomach?
Intrinsic Factor
Why is B12 deficiency rare?
5 yr supply is stored in the liver - usually only occurs in the elderly
How much folate do we store in our liver?
Only 1-6 month supply. We high a high daily requirement.
How does Vitamin B12 affect Folate?
VItamin B12 deficiency will cause a folate deficiency by preventing access to stored tetrahydrofolate.
What symptoms are associated with Vitamin B12 deficiency?
Megaloblastic anemia (pernicious anemia if due to intrinsic factor) and neurological damage. Correction of B12 def. can halt progression of neurological effects but cannot entirely reverse them. [Also folate supplements will reverse the anemia but not the neurological deficits - this is why its important that elderly people don’t take folate supplements unless we know they don’t have B12 def.]
